23 agosto 2012

Something essential has faded from discussion of the world’s most lethal sexually transmitted epidemic: Sex.

That’s a shame. Only by understanding how illness spreads can the world hope to prevent it. It’s not possible to understand how HIV spreads — why in some places one in four adults have the virus, and in others one in a thousand do — without understanding how variations in sexual behavior inhibit or accelerate its path through societies.

Within Africa, the epidemic exploded in places that had high rates of multiple partners and low rates of circumcision, along with modern transport routes to speed HIV along increasingly vast sexual networks.

The good news is that several of the hardest-hit African countries have experienced broad shifts in sexual behavior that caused the epidemic to slow measurably. Millions of infections have been averted by these shifts in behavior. The most famous is Uganda, where the “Zero Grazing” campaign in the late 1980s urged men and women to stick to their primary sexual relationships. But similar transformations have been measured in Zimbabwe, Kenya, Malawi and beyond.

Powerful antiviral drugs have, of course, allowed millions of people with HIV to live much longer, better lives. There is increasing evidence that this dramatic expansion in drugs can help prevent HIV. People receiving effective treatment are less likely to infect others, and giving medicine to high-risk people who are not yet infected — such as partners of people with HIV — appears to reduce transmission.

But the most powerful way to fight HIV is to target the factors crucial to its spread. Thankfully, after nearly two decades of resistance, global health programs have embraced the power of safe, voluntary circumcision programs to make men and their partners safer. Hundreds of thousands of men have received this service, with the aid of the US government and other donors.

There is no similar record on campaigns to address sexual behavior. Efforts often have gotten tangled in distracting ideological debates over the usefulness of condom promotion or abstinence campaigns. What has become lost is serious discussion about one factor that already has a proven track record of reversing HIV in Africa: warning men and women about the risk of having several ongoing sex partners.

It’s a subject few Westerners have wanted to discuss, and science about variations in sexual behavior has long gotten bogged down in accusations that those who explore this issue are moralizers eager to impose their values on others.

But the only value that matters in this debate is saving lives. Speaking explicitly about the role of sexual behavior in the spread of HIV does that, as Africans themselves have already demonstrated in several nations. When donors such as the United States support these efforts rather than shy away from the subject, they can be more effective.

Let’s not allow unease with the subject to undermine efforts to turn the world’s tinderboxes for the AIDS epidemic back into wet moss.